


Kill your Heroes

by hannibal_rises



Category: Big Hero 6 (2014)
Genre: Fix-It, Implied/Referenced Self-Harm, M/M, Sibling Incest, Time Travel, time portals
Language: English
Status: In-Progress
Published: 2015-01-19
Updated: 2015-01-20
Packaged: 2018-03-08 04:59:09
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 3
Words: 4,478
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3196190
Author URL: https://archiveofourown.org/users/hannibal_rises/pseuds/hannibal_rises
Summary: <blockquote class="userstuff">
              <p>Five years after Tadashi's death, Hiro and the Big Hero 6 are fighting a new enemy. Databorn, who has been stealing tech and using it against everyone leaving a slew of murder's in his wake. It seems, his target is Hiro... but who is he? And why was there a portal in one of the abandoned ships in the harbor, and why did it lead to where they lost Tadashi five years ago?</p>
            </blockquote>





	1. Fight, fight, baby fight

**Author's Note:**

> This is my first BH6 fic, and the plot has been in my head since the movie first came out. I'll be re-watching it to brush up on personalities and hopefully I'm not as bad as I think I am with them.  
> I'm taking on a lot with this, a lot of growing up, a lot of adjusting on all sides, a lot of sketches I need to make too. I'm planning on including sketches of everyone's updated armor, but I'm also horrible at drawing so it will take a lot of time for those.  
> I'm nervous about this one guys, please let me know if I'm doing good here. Thank.

“Hiro!” GoGo called after the teen, making the boy turn his head back, looking through the darkly tinted screen of his helmet to where she was. Her now long, dark hair spilling over her shoulders beneath her helmet. Her warning was just enough to get Hiro to side-swipe out of the way of a flying... well he just assumed it had been a knife, not planning to think harder on it. Databorn had been changing his weapons... appearance, everything between times they would fight.

With a hard hit of his heels against each other, the shoes board mechanism formed into a hoverboard. He had been using the board for over a month now, but the malfunctions continued to postpone his use of them. Now though? Now he didn't have a choice. Databorn was running into the ship's hull and he needed to be after him like, five seconds ago. The pick up time was slow on the board and he knew he was too far behind to actually catch him. They had been doing this dance for weeks! “Stay here, cover for Wasabi, has anyone seen Fred!?” Hiro asked, glad the coms were finally working.

“He's taking care of Honey, she got hit in the leg and because we left Baymax back at the lab for updates.” GoGo replied, as it were she tended to be the only one who would answer. “You go find him and kick his ass, Hiro!”

“Gladly.” Hiro answered, flying after DB.

Naturally, Hiro lost the trail, but the readings popping up on his helmet's screen told him of smoke, the sound of crackling reaching his ears. Fire? Where? All he knew was if there were fire, DB would likely be not only the cause but remaining close. What Hiro didn't expect was a portal. He thought the whole banning portals in San Fransokyo was actually working but no-o there had to be some asshole who actually kept one. “Guys, there's a portal back here, DB might have gone through it. I'm going in after him.”

“No! Hiro you know what happened last time you went into a portal! We lost the first Baymax! We don't want to loose you too!” Honey's strained voice came through his coms, making Hiro scowl.

“Then come here once everything is taken care of out there and cover me on this end. I have to try.” Hiro said, shifting his foot and accelerating the board, sending him surging through the portal, the sound of quiet static replacing Wasabi's protests.

 

There was smoke and flames everywhere, and somehow... Hiro felt some sort of... nostalgia just from passing through into the fire. As if... he had been here before. Looking around, he saw one person he hadn't seen in... four years. Callaghan. No. No it couldn't... “Professor Callaghan!” Hiro's head turned towards the door.

“Tadashi...” Hiro said before an alert appeared on the screen in his helmet. “Dashi!”

Tadashi coughed, running forward and blinking at the... man in armor on a hoverboard in a tinted helmet that looked- to him- like something was pulled out of Hiro's sketches. “Come with me.” Hiro said, reaching out to Tadashi. “Callaghan is safe, come with me before this place blows!” Hiro yelled, trying to keep his voice steady as Tadashi took his hand. The idiot always did trust too easily...

“S-shouldn't we be going toward the doors!?” Tadashi yelled through coughs until the portal came into his vision. “No way...”

 

“Hiro!? Hiro!?” Honey yelled at the coms, ignoring the way the others groaned.

“He can't hear us in there! Coms go down in portals.” GoGo reminded, frowning at the portal. “Now put the com back in your helmet and put it back on, we don't know when DB is coming back.”

“Speaking of coming back, get out of the way Honey, I think Hiro's coming back... what is that he's holding?” Wasabi said, tugging the blonde from in front of the portal when Hiro practically fell out of it, dropping Tadashi right on the ground.

“Oh... oh my god Tadashi!?” Honey screeched, dropping her helmet completely.

“Honey Lemon?” Tadashi asked, brows furrowed. “Your hair is shorter... why is yours short and GoGo's long? I just saw you like... fifteen minutes ago...”

“You... Hiro it was a time portal!” Honey said, turning to look at Hiro who's back was turned to the pair. “You- 'Dashi didn't die he came here... so he... was... oh that's confusing...”

“Time paradox- woah.” Fred said, his head off and poking at Tadashi. “Do you feel weird?”

“Oh my gosh you're alive!” Honey screeched again, hugging him tightly.

“Al... guys... what happened?”

“Get him out of here, it's not safe.” Hiro said, only tilting his head slightly. “You too Honey, you're hurt... DB is here som-”

Hiro's comments were interrupted by a swift hit, sending him flying to the side and crashing against the floor. “Hiro!” Wasabi exclaimed, standing. “Fred, get them out of here.”

“No.” Databorn's voice dripped, leaving them all turning to see him standing tall, holding Hiro by the helmet with a single strong hand. The teen's legs were flailing around as the board was cracked between them. “Look at him, Hiro. He's been gone for five years, dead for five years and suddenly here he is, right in front of you... and I'm going to take him away again.”

The sound of cracking had the entire group struggling to know what to do. Fred was helping Honey stand, Wasabi trying to hold GoGo back, knowing that if they moved, he would kill Hiro. Hiro who was struggling to get the just right angle with his legs... Finally, kicking his feet together, the flame rocket at the edge facing back at DB. The cracking grew louder, Hiro's head starting to pound at the pressure when the glass front finally gave way and cracked and fell away. “Hiro...” Tadashi gasped out, struggling to see his... baby brother suddenly so much older and... more or less struggling for his life. Hiro managed to kick back and dig the hot rocket edge against DB, falling firmly to the ground and pulling the helmet roughly off his head before turning, watching DB swear and run off.

“He's not about to get away this time...” Hiro swore, standing and rushing after DB.

“Hiro! Stop! We're not ready for him today.” Gogo said with a frown. “We need to report the portal... and... what we brought out of it...” She said, looking over to Tadashi, the rest of the group looking to him as well.

“Come on... let's get back to the labs... We have a lot to work on.” Hiro said, irritably ripping off his shoes and grabbing his helmet. “Maybe one day I'll actually make this stupid contraption work.”

 


	2. Nerd Lab 2.0

**Summary for the Chapter:**

> Tadashi observes the BH6 new lab before heading to The Lucky Cat to see Aunt Cass.

**Notes for the Chapter:**

> I mostly wanted to try to get a grasp of their personalities in this chapter, also wanted to try and point out the big differences between the BH6 movie where they were mostly based in the school and Hiro's house. Starting to get toward the actual personal issues in the next chapter. Why Hiro is so cold toward Tadashi, a lot of things being explained to Tadashi, and a surprise ender for the next chapter! I have a lot planned. Tags will be added but not until the next chapter is up because sPOILERS
> 
> Also I hope you enjoy a real look at the corkboard in the BH6 lab

Hiro had just graduated from SFIT that year, and with his friends all having graduated previously, the team had started renting out a lab to work in. Hiro and the others made a fair profit not only selling a few of their inventions, but working at the Lucky Cat with Aunt Cass. She had welcomed them with open arms and always offered her home for them if they needed it. After touring Tadashi around their new lab- his reactions to the updated Baymax totally worth it in Fred's opinion, the group rested and recovered. While Baymax treated Honey's leg, GoGo calmly scolded her for getting hurt, running her fingers through the Latina's shoulder length hair. “So... are you two finally..?” Tadashi asked, struggling to adjust to the whole... future everyone.

GoGo simply frowned over to him, but Honey Lemon smiled. “Yes. It took a while, didn't it?” She teased. “GoGo moves fast other than with matters of the heart.” She continued, giggling when she received a slap on the arm from said girl.

“And the hair..?”

“We both just wanted a bit of a change. I have to say I like it short. Less likely to get caught on something when we're fighting. Got my hair stuck in a Chem-Ball more than once.” She admitted with a laugh, looking at Baymax when he stood from where he knelt to tend to her leg.

“No more fighting for Honey Lemon for two weeks.” His soothing, robotic voice said. “Now to tend to Hiro. Are you satisfied with your care?”

Honey simply continued to smile. “Not yet.” She said, opening her arms to the inflated robot. Baymax wobbled over to her, giving her a hug. “Now I'm satisfied with my care.” She said, patting his “head”.

With that Baymax wobbled over to where Hiro sat disassembling his broken helmet. “Hiro.” Baymax greeted, more firmly than he thought he would have anyone else, likely programmed to do so just to keep Hiro in line enough to obey.

“Hiro updated Baymax a lot over the years. A portable version for house holds was in the works, but in the end he never made one. We still only have the one Baymax.” Wasabi said, crossing his arms. “But I swear, it's like he learns and knows emotions. It's freaky, but in a good way.”

“So... Hiro didn't reprogram him to act the way he is now?” Tadashi asked, looking at his brother like he was a stranger. The brother he knew awed at Baymax, laughed and called him a nerd. This young man sitting at a lab table and working at his equipment while Baymax scans and tends his head? Tadashi did not know him.

“Oh hell no. Hiro hates it when he acts this way. Threatened to reprogram him to make him stop more than once.” GoGo said, blowing a bubble and letting it pop. “But it gets him taken care of, which is all we really want.” She said with a shrug.

There was silence for a few moments, Tadashi looking around the lab to take everything in. That's when he paused at a cork board, feeling like his chest was about to clench. At the center was the photo they had just taken that day... or... five years ago? To Tadashi it felt like so short a time ago, but there was an obvious ware on the photo and they looked so different.. Different selfies surrounded it, as well as Baymax's blueprint and... Tadashi's student ID. It was discolored and laminated to a piece of paper, the fire having taken it's toll on the ID. He must have... “You dropped it just outside the doors. I did that. Laminated it and everything.” Fred said, oddly calm.

“Wasabi... why is your face covered in the picture on the corner?” Tadashi asked, a small smile forming on his face.

“Oh don't you dare lift that-” Wasabi started, letting out a groan as Tadashi walked over and did just that.

Tadashi cringed and looked over to him. “How did you manage that?” He asked with a small laugh. In the photo, Wasabi's nose had been badly bruised, likely broken, and it seemed to have swollen his entire face. Even in the picture he looked upset about Hiro taking the selfie.

“I was sparring with GoGo. I really regretted it, she even cracked it back into place.”

“Of course I did. You where whistling when you breathed in through your nose.”

“Ew, okay ow.” Tadashi interrupted with a small laugh. It seemed they hadn't really changed... not too much.

A sudden ringing filled the air, Honey picking up her cellphone and greeting whoever was on the other end. “Hiro! Is your phone off?” She called out with a frown. “Aunt Cass says you were supposed to head over tonight for dinner, and now we're all invited.”

“Oh great.” Hiro groaned, head dropping to the table with a loud thump, Baymax protesting in his mechanical voice. “I completely forgot and I was updating my phone it's over here, crap.”

“We're coming over now. Ooh! Aunt Cass we have a surprise for you!” Honey practically screeched, bouncing at the realization. “No, no you'll see! Just... be sitting down when we get there okay? Okay we'll be over right away!” With an excited squeal, Honey bounced to her feet and threw her arms around Tadashi, ignoring the way her injured leg protested. “She's going to be so happy!”

“If she doesn't have a literal heart attack. Come on, Baymax, you're coming with us. I'm satisfied with my care.” Hiro said, holding his hands out as Baymax seemed to deflate to nothing but his head, which floated into Hiro's hands and blinked up to him.

“Wi-ings?” Baymax questioned almost excitedly, making Hiro laugh, and though no one noticed it, Tadashi's tense shoulder's seemed to relax.

“No, Baymax, wings are next week. We're on a schedule with them now since she got so much heartburn she was crying and you started to fritz.” Hiro reminded, lightly knocking on the bot's head with his knuckles. “Honey, get off that leg, I'll grab the crutches.”

Honey just stuck her tongue out at Hiro and let out a laugh, leaning against the table as Baymax's head floated toward them. “This is... interesting.” Tadashi said, taking Baymax's head in his hands.

“It was Fred's idea, actually. Baymax took up too much space, his response time to injuries was slow in crowded areas so he said-”

“What if like, just his head floated around and he blew up to help us!” Fred chimed in, interrupting Wasabi, making the much taller man lightly hit Fred in the chest. “And so he like, did it. It's pretty cool!”

“Yeah... it really is.” Tadashi said, smiling at the Baymax head, which simply blinked back up at him. Honestly, Tadashi hadn't thunk that far ahead.

“I wanted to keep your original base for him...” Hiro said, not able to look Tadashi in the eyes as he handed Honey the crutch. “So I wasn't willing to take too much out of his form. This is Baymax version three though. We lost one in a portal, but managed to keep his healthcare chip. We made copies before we lost two, thankfully.”

“And what happened to version two?” Tadashi asked, a bit of brotherly irritation floating into his voice, and like always, Hiro's ears shifted back slightly at the scolding.

“We don't talk about version two.” Honey said with a nervous laugh.

“Trust me 'Dashi.” Wasabi said, resting his large hand on Tadashi's shoulder. “You don't want to know. Fred, don't tell him, you shouldn't have told me, but you did, and now I'm telling you-” Wasabi went from pointing to Fred to Tadashi. “You don't want to know.”

“Come on, I'm hungry guys let's just head to Aunt Cass' already.” GoGo said, hopping from where she sat and grabbed her jacket. “Are we all taking Wasabi's car or are we going to have to split?”

“Well, with Baymax deflated everyone should fit.” Wasabi said with a shrug.

“Don't tell me after all these years you still have that tiny litte-” Tadashi started with a small laugh before everyone seemed to give him the same look. “What? Listen, I know next to nothing about this right now okay, don't give me that look.”

“My. Baby.” Wasabi started, seeming like he was personally offended. “Has gotten us through so much. It's been chased at high speeds, thrown into the ocean, crashed into another car on many an occasion and it still keeps us going.”

“Yeah, about that, we're taking Honey's car.” GoGo said, popping another bubble. “Because I really do not want the bad luck that follows your car to get in the way of dinner.” She said, patting Wasabi's shoulder and walking away, smirking as Fred and Hiro laughed.

“I'll let you drive, Wasabi, don't worry.” Honey tried to comfort as they moved toward the door.

Hiro kept his hands firmly in his pockets as they walked, eyes trained at the ground. He couldn't look at Tadashi... he couldn't bring himself to. He was back... alive... but that meant... Hiro took Tadashi from himself... He could change their entire timeline. He could built a time machine and send Tadashi back... back to him... “You're thinking too much.” Tadashi said suddenly, making Hiro look to him with wide eyes. “Oh come on, you may be a lot older now but... you still make the same faces. And that one? You're thinking about something you already know the answer of but are trying to change. Come on, Hiro...” Tadashi blinked as Hiro suddenly frowned and started walking briskly away from him. Why was Hiro avoiding him? If it really had been five years... Maybe Aunt Cass had the answers.

 

 


	3. Saturn

**Summary for the Chapter:**

> Ah yes, the chapter I've thought most about since this whole mess started.  
> Warning: Hints to self-harm, and non-main character death.  
> I also wrote this to the song Saturn by Sleeping at Last so it's unnecessarily sad. Fight me.

As it were, Aunt Cass almost fainted. Then she proceeded to cry and hold Tadashi for at least fifteen minutes while everyone else ate. Finally, when everyone was gone, Tadashi helped Aunt Cass wash up and finally asked what was on his mind. “Aunt Cass... what happened? After the fire... For you all?”

“You didn't ask Hiro?” She asked, a hint of relief in her voice.

“No he's been... distant.” Tadashi admitted, looking over to where Hiro went upstairs, Tadashi assumed to their room.

Cass simply nodded. “Well, it's understandable. You know, we assumed you were dead. We buried an empty casket, there was nothing left to bury. It seems that's because you're here.” She said with a light slap to his chest with a wet hand. “I don't understand all the big science behind it, but you know that already. That hasn't changed.. Naturally... Hiro was crushed. It took him until last year to tell me the whole story but the only thing that really kept him functioning was Baymax. Apparently someone started the fire to steal his microbots, and they succeeded. That person was actually Callighan.” She said, looking over him to Tadashi with a curious look, wanting to see his reaction.

Tadashi had stopped washing the dishes, only stood there with a disbelieving look. “He couldn't... no Professor Calli-”

“Was out to avenge his daughter.” Hiro chimed in from the stairs, frowning. “I blamed him... for your death.” Hiro made a point to make eye contact with Tadashi at this comment. “But blablabla, long story short we put him behind bars, rescued his daughter who was actually alive the whole time and kind of fell into the hero gig.” He said with a wave of the hand. “Somehow kept it from Aunt Cass until last year. You're nowhere near caught up but you're smart, you'll be caught up in no time.” He continued, walking the rest of the way down the stairs. “The room is all ready, all your stuff is still in boxes in the closet...We couldn't sell it or really take it to the garage so it should all be there, if not I might have one or two things.”

“He's still a dirty little thief.” Aunt Cass teased, smiling to Tadashi before looking to Hiro. “Do I get a hug before you go?”

“Of course, Aunt Cass.” Hiro said, walking over to them with long strides before wrapping his arms around her, letting out an “ewwwww” at her wet hands when she hugged back.

“Where are you going..?” Tadashi asked after a moment of almost awkward silence, feeling like he was missing out on something important.

Hiro blinked at him a few times before finally speaking. “Home?” He offered like Tadashi should know. “Come on, Dashi, how many times did I mention that when I was your age I would get a place to not have to burden Aunt Cass anymore?”

“Never.” Tadashi answered flatly, the two blinking at each other before Hiro let out a nervous laugh.

“Okay, yeah she kind of kicked me out.” Hiro admitted. “I was sulking and refusing to go to classes last year so she demanded I get up get a place and sulk there. So I did, only that was enough to get me off my butt, and she knew it would be. I didn't feel right moving back, so I live close and we see each other almost every day anyway.” He admitted with a laugh, laughing more when Aunt Cass batted at him with the towel.

“He's making me look bad. I tried to think what would get him to stop without babying him still. Not that I still don't just look at his cute widdle face.” She cooed, reaching out and pinching Hiro's cheek, making the boy groan. In that moment, Tadashi felt more at home than he had in the last few hours.

Finally managing to pull away, Hiro sighed. “I need to head out, Mochi the second needs feed, he's going to hate me.”

“Mochi the second?” Tadashi asked, following Hiro as he walked, wanting to get a private moment with him.

“Yeah it ended up Mochi was a girl. Who knew.” He said with a shrug, looking at Tadashi almost nervously when he noticed they were alone. Suddenly he understood why Tadashi intimidated him now. What if he was a disappointment to him?

“Hiro... I want to know... can you take me back? To the past that is... to when I should be?” Tadashi asked, sliding his hands in his pockets, hoping the math that was building in his head was wrong...

Hiro shook his head solmnly. “You... 'Dashi you never came back. I never saw you again until... well today.” He admitted sucking on his teeth awkwardly. Just thinking about it hurt his chest... that was until he was suddenly pulled into a tight hug.

“Then I guess it was a long time since you got one of these from me, huh?” Tadashi said, placing a hand on the back of Hiro's head, smiling as he held his now much taller brother. Yeah, Hiro was still shorter than him... but not by much, and his hand could feel that Hiro's hair was much shorter in the back and was that... an undercut? He was about to question it when he felt Hiro's shoulders shake. Suddenly, hands gripped the back of his shirt and the shoulder grew damp where Hiro's face was pressed. “Hiro...”

And just like that Hiro was pulling away from Tadashi's arms, almost violently rubbing at his face to stop the tears. “I'll... see you tomorrow, Tadashi...” He said tensely, turning and walking out the door. Tadashi just blinked helplessly after him. The quiet rumble of an engine started and a car pulled from the street away from the home and Cafe.

“Tadashi, close the door please.” Aunt Cass' voice came suddenly, breaking Tadashi from his haze. He closed the door and blinked a few times. The last time he saw Hiro cry... the boy was tiny and being bullied at school. “Come in here, let me show you your room.” Cass called from the stairs, making Tadashi turn and head toward the stairs again.

They traced the familiar steps to his room, and for some reason Tadashi expected it to be exactly like it was to him that morning....

 

Hiro unlocked his quiet studio apartment, blinking as he turned on the lights, a soft, quiet meow sounding as Moshi II paced around his ankles, rubbing his neck up Hiro's leg. “I'm home...” He greeted quietly.

 

“We turned it into a guest bedroom for whenever one of the group needed a place to stay. Sure, they could have gone to Fred's place but I guess they just like me best.” Cass said with a smile, Tadashi looking around the almost bare room. Hiro's desk was still in the corner, but it was cleared off, a few books he left behind on the table neatly placed.

 

Hiro dropped his keys in the bowl by the door, toeing his shoes off and padding over to the sad excuse for a kitchen. “I know, I know, you're hungry.” He said, pulling the cat food from a bottom cupboard and filling the small cat bowl with it.

 

The bed was a full size, likely Tadashi's old one. The sheets were a simple blue, the bed where Hiro's always was. Curiously, he peaked to the other side of the room, where his bed used to be. There were simply stacks of boxes, some marked with a simple H, likely things Hiro left behind... His desk and drawing table were still there, behind some of the boxes. “I'll just leave you here then...” Aunt Cass said, suddenly tearful.

 

Hiro ran a hand through his messy hair, looking over to his unmade bed, the books open across the mattress. A simple picture of he and Tadashi when they were younger pinned to the wall right next to the bed. The number of nights he woke up crying to see that image... He though he forgot what Tadashi's voice sounded like...

 

Tadashi let out a hum, nodding as Cass closed the door, moving to one of the boxes marked with an H. He opened the top and let out a strained noise. Right on top was Hiro's bot... the one that inspired the microbots... If what they said was true... then Callaghan used them against Hiro... used his own invention against him. And Tadashi had run in to save him... Picking up the limp bot in his hand, Tadashi sighed.

 

Hiro choked out a small sob, rubbing the tears roughly from his eyes. He hadn't wanted to cry... he couldn't cry... He walked quickly to the bathroom, slamming the door needlessly behind him. Digging into the medicine cabinet, Hiro pulled out the razor blades he kept simply for moments like this. When nothing felt real. When the pain in his chest was all he could feel...

 

There was a picture beneath the bot... in fact there were several. Hiro and a young woman. She had waves of ginger hair, a wide smile and brilliant blue eyes. They looked happy together... these photos couldn't have been a year old. Between the photos fell a news clipping. At least- it seemed- they still had news papers....

 

Once Hiro was cleaned, his arms washed properly and the few bandages he needed in place, he zombie walked himself over to his bed, flopping onto it and curling into a ball, his face pressing into the cool pillow. With a soft 'meow' Mochi II struggled to climb into the bed, only succeeding after the forth attempt, walking over Hiro's legs and curling in the curve at his chest.

 

It was an obituary. The grainy photo Tadashi could see better in his other hand... it was the girl. A car accident. Last year. When Aunt Cass had to kick Hiro out. Scanning over the article, Tadashi finally located a name. “Belladonna Dane.” He tried it on his lips, frowning deeply. “Where do I know that name from..?”

 

Hiro's shoulder's shook and he clung to Mochi II. The only thing he could think about was the possibility that now that Tadashi was back... he would loose him again...

 


End file.
